本文選題：下丘 + 豚鼠　； 參考：《中國人民解放軍軍醫(yī)進修學院》2010年博士論文

【摘要】： 目的：觀察噪聲暴露耳蝸損傷后豚鼠下丘神經(jīng)元對純音刺激編碼機制的改變以及神經(jīng)遞質(zhì)r-氨基丁酸(GABA)的改變,闡明噪聲性耳鳴、聽覺過敏、響度重振等癥狀發(fā)生的機理。研究分三部分： 一、正常豚鼠下丘的電生理特性。研究發(fā)現(xiàn)：1.大部分頻率地形圖(FRA)為V-shape型(84.89%),其余為non-V-shape型。2.沿背腹軸方向,隨著深度的增加,特征頻率(CF)呈階梯式增加。特征頻率與其閾值(MT)的函數(shù)關(guān)系呈U形即低頻和高頻部分閾值較高。特征頻率的閾值由淺到深總體表現(xiàn)為“V”型。3.反應(yīng)率-強度函數(shù)(RIF)有五型：a)u1型,反應(yīng)率-強度函數(shù)曲線緩慢上升到最大反應(yīng)程度,最后呈下降趨勢；b)u2型,反應(yīng)率-強度函數(shù)曲線緩慢上升到最大反應(yīng)程度。c)u3型,快速上升-平緩型,函數(shù)曲線快速上升,在30dB-40dB刺激強度時,反應(yīng)率達到高峰,然后維持這一高度或緩慢上升直到最后。d)ud型,函數(shù)曲線快速上升,在30dB-40dB刺激強度時,反應(yīng)率達到最高峰,然后快速下降,呈倒U形。e)N型,函數(shù)曲線形狀呈N、M或W形。4.刺激后時間直方圖(PSTH)有五型：A.抑制型,在純音刺激過程中抑制自發(fā)放電。B.瞬態(tài)型,在純音刺激最初25秒之內(nèi)呈現(xiàn)興奮反應(yīng),隨后在整個刺激過程中跟著低放電。c.長潛伏期型,類似瞬態(tài)型,但有一個22ms的潛伏期,后面的波峰較寬。D.暫停／發(fā)放型,a.起初高的放電,緊接著短暫的下降,隨后跟著中等程度的持續(xù)放電；b.長潛伏期接著一個平穩(wěn)的放電。E.發(fā)放型,從一開始就出現(xiàn)較高的反應(yīng),有平穩(wěn)的放電。 二、噪聲暴露后下丘的電生理改變：1.耳蝸損傷模型可靠。2.從震后1天開始,雙峰型FRA和狹窄型FRA明顯增多；震后11-21天,狹窄型FRA減少。3.CF與深度函數(shù)圖中,在相當于4KHz的頻率段有一個明顯的斷層,象正常組那樣隨著深度的增加cF呈階梯式上升的規(guī)律被破壞,階梯變平緩。4.cF平均持續(xù)深度比正常組明顯增加。5.大多數(shù)頻率段,震后組cF閾值較正常組均低。6.噪聲暴露后1天內(nèi),特征頻率閾上20dB帶寬(BW20)沒有增加,反而略降低；震后11天-21天,平均BW20比正常組明顯增加。7.RIF的類型和正常組相同,但構(gòu)成比例不同,隨著震后時間延長,漸趨相同。8. PSTH的類型和正常組相同,但構(gòu)成比例不同,隨著震后時間延長,漸趨相同。 三、噪聲暴露后下丘的GABA改變：GABA神經(jīng)元和GABAA、GABAB受體較正常組明顯減少,隨著時間延長,有所增加。 結(jié)論：噪聲性耳鳴、聽覺過敏、言語分辨率下降的生理基礎(chǔ)可能是下丘神經(jīng)元調(diào)諧曲線變寬或變窄、發(fā)放類型改變、反應(yīng)興奮性增加,其物質(zhì)基礎(chǔ)之一是抑制遞質(zhì)GABA減少。
[Abstract]:Aim: to observe the changes of pure-tone stimulation coding mechanism of inferior colliculus neurons and the change of neurotransmitter r-aminobutyric acid (r-aminobutyric acid) after noise exposure to cochlear injury in guinea pigs, and to elucidate the mechanism of noise-induced tinnitus, auditory hypersensitivity and loudness. The study is divided into three parts: 1. Electrophysiological characteristics of inferior colliculus of normal guinea pigs. The study found that 1: 1. Most of the frequency topographic maps (FRAA) are of V-shape type 84.89, and the rest of them are non-V-shape type. 2. Along the direction of the dorsal abdomen axis, the characteristic frequency and CFS increased step by step with the increase of depth. The function relationship between the characteristic frequency and its threshold value (MTT) is U-shaped, that is, the low frequency and high frequency partial thresholds are higher. The threshold of characteristic frequency from shallow to deep is "V" type. 3. There are five types of reaction rate-strength function (RIF-1). The curve of rate-intensity function rises slowly to the maximum reaction level, and finally shows a downward trend. The curve of RIF-intensity function rises slowly to the maximum reaction degree, and the curve of responsibility-intensity function rises slowly to the maximum reaction degree. The function curve rises rapidly, and at the intensity of 30dB-40dB stimulation, the response rate reaches a peak, and then maintains this height or rises slowly until the last type. The function curve rises rapidly, at the intensity of 30dB-40dB stimulation. The reaction rate reached the highest peak and then decreased rapidly, with the shape of inverted U. Ebony N, and the shape of function curve NM or W. 4. The time histogram (PSTH) after stimulation has five types: A. Inhibition of spontaneous discharges during pure tone stimulation. Transient response was observed during the first 25 seconds of pure tone stimulation followed by low discharge. Long latency type, similar to transient type, but with a 22ms latency, the latter peak is wider. D. Suspension / distribution type. Initial high discharge followed by a brief decline followed by moderate sustained discharge b. A long incubation period followed by a steady discharge. Release type, from the beginning there is a higher response, there is a steady discharge. Second, the electrophysiological changes of inferior colliculus after noise exposure: 1. The model of cochlear injury is reliable. From one day after the earthquake, the bimodal FRA and narrow FRA increased obviously, the narrow type FRA decreased .3.CF and the depth function diagram in 11-21 days after the earthquake, there was an obvious fault in the frequency region corresponding to 4KHz. As in the normal group, with the increase of the depth, the law of step by step rise of CF was destroyed, and the average continuous depth of the ladder flattened. 4. The mean duration depth of CF increased significantly than that of the normal group. In most frequency regions, the cF threshold of the post-earthquake group is lower than that of the normal group. Within one day after noise exposure, the 20dB bandwidth on the threshold of characteristic frequency (BW20) did not increase, but decreased slightly, and the average BW20 increased significantly between 11 and 21 days after the earthquake compared with the normal group, the type of BW20 was the same as that of the normal group, but the proportion was different, and with the extension of the post-earthquake time, Tend to be the same. The type of PSTH is the same as that of normal group, but the proportion of PSTH is different, and with the extension of post-earthquake time, it gradually tends to be the same. 3. The changes of GABA in the inferior colliculus after noise exposure were significantly lower than those in the normal group. Conclusion: the physiological basis of noise-induced tinnitus, auditory hypersensitivity and decreased speech resolution may be the broadening or narrowing of the tuning curve of the inferior colliculus neurons, the change of the distribution type and the increase of the excitability of the response. One of its material bases is to inhibit the decrease of GABA.
【學位授予單位】：中國人民解放軍軍醫(yī)進修學院
【學位級別】：博士
【學位授予年份】：2010
【分類號】：R764

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本文編號：1958378